A string of natural length L extends to a new length L' under tensile force F. If Hooke’s law applies, the work done in stretching the spring is _________________

The work done in stretching the spring can be calculated using the formula for work, which is given by:

Work = Force x Displacement

In the case of Hooke's law, the force is directly proportional to the displacement or extension of the spring. Therefore, we can write the force as:

F = kΔL

where k is the spring constant and ΔL is the change in length.

Given that the natural length of the spring is L and it extends to a new length L', the change in length is:

ΔL = L' - L

Substituting this into the equation for force, we get:

F = k(L' - L)

Finally, we can calculate the work done by multiplying the force by the displacement:

Work = F x ΔL

Work = k(L' - L) x ΔL

Therefore, the work done in stretching the spring is k(L' - L) multiplied by the change in length, ΔL.